BOSTON -- Alfredo Aceves had blown three of his last five save chances entering Friday, but the right-hander will remain the Red Sox's closer for now.

When the Red Sox acquired Andrew Bailey from Oakland during the offseason, the club envisioned he would be their closer in 2012. But Bailey underwent surgery on his right thumb the day before the season started and Aceves took over that role.

Bailey made his season debut on Aug. 14. He's allowed one run on three hits in four appearances, with four strikeouts in two innings.

Red Sox manager Bobby Valentine needs to see more from Bailey, though, before he considers making him his closer.

"I wish he had a little more [appearances] so I could make that determination," Valentine said before Friday's series opener against the Royals.

In his first season as a closer, Aceves has 25 saves in 32 opportunities. He's 2-8 with a 4.60 ERA. He took the loss and blew a save in Thursday's 14-13 defeat against the Angels.

Aceves has made a career-high 58 appearances with 62 2/3 innings this year. On Thursday, he allowed five runs on six hits, including two homers in one-plus innings.

Is Aceves showing signs of fatigue?

"No, I've even heard that he hasn't pitched enough and that's part of the problem with his command," Valentine said. "His stuff is there, just according to the catchers it's down the middle, that's not a good place to be."

What has been Valentine's evaluation of Bailey since he returned from injury?

"I think he's pitched well every time he's been back," the manager said. "He's gaining command and confidence."

Papi makes immediate impact in his return

BOSTON -- David Ortiz fulfilled his promise to put on a show in his first game with the Red Sox in over a month.

"You all can sit back and enjoy the show tonight," Ortiz said before Friday's 4-3 win over the Royals in the series opener.

In the lineup for the first time since straining his right Achilles tendon on July 16, Ortiz lined the first pitch he saw from Royals left-hander Bruce Chen up the middle for a two-run single to give the Red Sox a 2-0 lead in the first inning.

Ortiz belted a double in his next at-bat, also on the first offering from Chen. "He looked like a sight for sore eyes," manager Bobby Valentine said. "He proved that you didn't need a rehab assignment, and the first two pitches that he saw he drove both of them nicely, one for two RBIs.

"It was very impressive. David is world-class and world-class players can do special things."

Ortiz missed 35 games with the injury and the Red Sox went 13-22 without him in the lineup. He was still bothered somewhat by the strain and was not at full strength running the bases. "We'll see how it goes the next couple of days," Ortiz said. "I want to give it a try and see how it feels the next couple days."

Still, the Red Sox are glad to have their slugger back no matter how healthy he is. Ortiz leads the club with a .318 average and 23 home runs. He also has a 12-game hitting streak.

"It's big. Anytime he's in the lineup, it's big for us," said starter Jon Lester, who won his eighth game of the season. "He's a big offensive threat. Obviously, he's a presence. The presence is more than anything. You can tell it's still bothering him a little bit, but he's still out there doing what he can."

In a corresponding roster move, the Red Sox optioned right-hander Junichi Tazawa to Triple-A Pawtucket.